The present invention relates in general to electroerosion milling (EEM), and more specifically to an adaptive spindle that modifies a Computer Numerical Control (CNC) machine tool, such as a CNC milling machine for EEM.
Electroerosion machining is performed by passing an electrical current through a gap between an electrode and a workpiece for removal of material on the workpiece. It uses direct-current (DC) voltages to electrically power removal of the material from the workpiece. An electrolyte is circulated between the tool electrode and the workpiece to facilitate electroerosion of the workpiece material, and to cool and flush the gap region. This process enables a high rate of material removal with low thermal damage to the workpiece. An advanced form of electroerosion machining using a spinning tool electrode is described in related U.S. patent application Ser. No. 10/842,344.
EEM provides quicker machining and higher efficiencies than mechanical cutting or other electrical discharge machining (EDM) methods in various applications, such as turbine impeller and bladed disk roughing and machining. It is believed, however, that prior to the present invention there has been no practical way to convert a conventional CNC milling machine for EEM operation. Thus, EEM machines to date have been specialized systems.